code: def _test_function(x: float, y: float) -> float:
      return x**2 + y**2
  
file_path: spark/python/pyspark/ml/tests/test_dl_util.py
imports: from contextlib import contextmanager
  import os
  import textwrap
  from typing import Any, BinaryIO, Callable, Iterator
  import unittest
  from parameterized import parameterized
  from pyspark import cloudpickle
  from pyspark.ml.dl_util import FunctionPickler
label_desc: Use image node_id 1 for calling the TestFunctionPickler obj's underlying member method code with example usage: obj._test_function(x, y) and returns: unknown